Experimental and theoretical studies of trace species in Earth materials, from mantle geodynamics to environmental applications and mineral exploration

矿物和其他地球材料（如熔体和流体）中的微量物质，如取代或间隙离子/分子、空缺和辐射引起的缺陷，代表着早期的辐射损伤，对物理性质，如颜色、密度、流变性、稳定性、导电性和导热性、磁性、地震速度等产生深远影响。地球材料中的痕量物种在固体和环境地球科学中也有广泛的应用，从地球化学建模到辐射剂量学、地质年代学、重金属/类金属污染的修复、核废料处理和矿物勘探。该研究项目的长期目标是对地球材料中痕量物质的定量和机械理解，重点是它们的几何和电子结构、物理性质和应用。科学方法包括实地调查，以确定对地质过程重要或与环境和技术应用直接相关的特定痕量物种。实验室实验的目的是补充实地研究，并为光谱研究提供合成材料，这往往是不可能的自然样品。通过使用多种最先进的分析技术，如电子顺磁共振、红外、拉曼、核磁共振和同步加速器x射线吸收光谱，以及周期性第一性原理计算和第一性原理分子动力学模拟，对选定矿物和熔体中的痕量物种进行了表征。下一个资助周期的具体目标是：1)石英和其他二氧化硅辐射缺陷的性质及其在矿产勘探中的应用；2)与环境应用和地幔地球动力学相关的从地表到下地幔条件的碳酸钙矿物和碳酸盐岩熔体中痕量物种的影响；3)造岩矿物和硅酸盐熔体中的溴系统及其在岩浆-热液矿床中的应用。这个关于地球物质中微量物质的机理认识的研究项目在加拿大是独一无二的，在实验和理论的前沿探索上都是创新的。此外，该研究项目为在多学科环境中培养高素质人才（HQP）提供了极好的机会。这个研究项目的多学科性质体现在高质量HQP的吸引力，他们具有从化学到工程、地质、地球物理、材料科学和物理等不同学术背景，与化学家、材料科学家和物理学家有深入的合作，我们不仅在地球科学期刊上发表了论文，还在化学、材料科学和物理方面发表了论文。

Trace species, such as substitutional or interstitial ions/molecules, vacancies and radiation-induced defects representing incipient radiation damage, in minerals and other Earth materials (e.g., melts and fluids) exert profound impacts on physical properties such as color, density, rheology, stability, electrical and thermal conductivity, magnetism, seismic velocity and many more. Trace species in Earth materials also have wide applications in solid and environmental Earth sciences from geochemical modeling to radiation dosimetry, geochronology, remediation of heavy metal/metalloid contamination, nuclear waste disposal and mineral exploration. The long-term objective of this research program is directed towards quantitative and mechanistic understanding of trace species in Earth materials, with emphasis on their geometric and electronic structures, physical properties, and applications. Scientific approaches include field-based investigations to identify specific trace species important to geological processes or directly relevant to environmental and technological applications. Laboratory experiments are designed to complement field-based research and to provide synthetic materials for spectroscopic studies that are often impossible for natural samples. Trace species in selected minerals and melts are characterized by use of multiple state-of-the-art analytical techniques, such as electron paramagnetic resonance, infrared, Raman, nuclear magnetic resonance and synchrotron X-ray absorption spectroscopy as well as periodic first-principles calculations and first-principles molecular dynamics simulations. Specific objectives for the next funding cycle are: 1) nature of radiation-induced defects in quartz and other silica with applications to mineral exploration, 2) effects of trace species in calcium carbonate minerals and carbonatitic melts from surface to lower-mantle conditions with relevance to environmental applications and mantle geodynamics, and 3) bromine systematics in rock-forming minerals and silicate melts with applications to magmatic-hydrothermal ore deposits. This research program on mechanistic understanding of trace species in Earth materials is unique in Canada and is innovative in exploring the frontiers of both experiments and theories. Also, this research program provides an excellent opportunity for highly qualified personnel (HQP) training in a multidisciplinary environment. The multidisciplinary nature of this research program is demonstrated by the attraction of high-quality HQP with diverse academic backgrounds from chemistry to engineering, geology, geophysics, materials science and physics, in-depth collaborations with chemists, materials scientists and physicists, and our publications in not only Earth science journals but also those in chemistry, materials science and physics.